POS1549 BETTER DRUG SURVIVAL ON MONOCLONAL ANTIBODIES COMPARED TO ETANERCEPT IN FIRST LINE ANTI-TNF THERAPY IN PATIENTS WITH PSORIATIC ARTHRITIS MAY BE DUE TO DIFFERENTIAL THERAPEUTIC RESPONSE IN SKIN INVOLVEMENT: A PROPENSITY SCORE-MATCHED ANALYSIS FROM THE NATIONWIDE CZECH ATTRA REGISTRY
Authors: Š. Tichý, L. Nekvindová, J. Baranová, K. Pavelka, P. Horak, J. Vencovský, J. Zavada
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Etanercept is an agent of specific molecular structure and its efficacy in extraarticular disease differs from monoclonal antibodies. This could affect drug survival in some rheumatic diseases with a larger presence of extraarticular involvement. <h3>Objectives</h3> To compare the drug survival of etanercept to monoclonal anti-TNF antibodies in psoriatic arthritis and describe the response of skin disease to treatment in the two groups. <h3>Methods</h3> Patients with PsA starting first-line biological treatment from 01/01/2012 to 30/06/2020 were enrolled from the Czech ATTRA registry and split into two groups as either being treated with etanercept (ETA) or any other anti-TNF. Propensity scores were calculated using covariates based on statistically significant differences in the baseline characteristics and clinical relevance (Table 1). PS was then used to match 81 etanercept to 160 other TNFi patients. We performed a Kaplan-Meier survival analysis and checked for statistical significance using the log-rank test. We calculated survival rates at set time points, median survival time in each group and the hazard ratio of etanercept for drug discontinuation. The Physician global assessment of psoriasis variable (measured on a numerical rating scale 0-5) was sorted in categories of mild (0-1), intermediate (2-3) and severe (4-5) and respective percentages were calculated in the propensity-matched groups at 3, 6, 12 and 24 months. Pearson's chi-squared test or Fisher's exact test were used to check the differences for statistical significance. <h3>Results</h3> We found significantly worse drug survival on ETA compared to other TNFi at each time point (Figure 1). The median survival time on ETA was 35.8 (95% CI 25.1 – 46.6) months compared to 65.7 (95% CI 51.9 – 79.6) months on other TNFi. The HR of ETA for treatment termination was 1.61 (95% CI 1.11 - 2.34), p=0.011. At baseline, there were no differences in skin disease severity. The percentages of mild, intermediate and severe skin disease were 22.2%, 59.3% and 18.5% on etanercept and 25.0%, 55.6% and 19.4% on other TNFi, p=0.853. At 3 months, skin disease was significantly more severe in ETA with 50.0%, 44.8% and 5.2% compared to 76.2%, 23.8% and 0% on other TNFi, p&lt;0.001. At 12 months, the respective percentages were 66.6%, 31.9% and 2.1% on ETA and 84.7%, 15.3% and 0% on other TNFi, p=0.015; at 24 months 62.9%, 37.1% and 0% compared to 84.9%, 15.1% and 0%, p=0.010. <h3>Conclusion</h3> Etanercept had worse drug retention than monoclonal antibodies in PsA. Patients treated with ETA had more severe skin disease during follow-up compared to those treated with other TNFi, which could lead to earlier switching to another drug. <h3>Acknowledgements</h3> This work was supported by the project (Ministry of Health, Czech Republic) for conceptual development of research organization 00023728 (Institute of Rheumatology). <h3>Disclosure of Interests</h3> None Declared.